/*
 * WPA Supplicant - Scanning
 * Copyright (c) 2003-2008, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "eloop.h"
#include "config.h"
#include "wpa_supplicant_i.h"
#include "mlme.h"
#include "wps_supplicant.h"
#include "ctrl_iface_dbus.h"


static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
{
        struct wpa_ssid *ssid;
        union wpa_event_data data;

        ssid = wpa_supplicant_get_ssid(wpa_s);
        if (ssid == NULL)
                return;

        if (wpa_s->current_ssid == NULL)
                wpa_s->current_ssid = ssid;
        wpa_supplicant_initiate_eapol(wpa_s);
        wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
                   "generating associated event");
        os_memset(&data, 0, sizeof(data));
        wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
}


#ifdef CONFIG_WPS
static int wpas_wps_in_use(struct wpa_config *conf,
                           enum wps_request_type *req_type)
{
        struct wpa_ssid *ssid;
        int wps = 0;

        for (ssid = conf->ssid; ssid; ssid = ssid->next) {
                if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
                        continue;

                wps = 1;
                *req_type = wpas_wps_get_req_type(ssid);
                if (!ssid->eap.phase1)
                        continue;

                if (os_strstr(ssid->eap.phase1, "pbc=1"))
                        return 2;
        }

        return wps;
}
#endif /* CONFIG_WPS */


int wpa_supplicant_enabled_networks(struct wpa_config *conf)
{
        struct wpa_ssid *ssid = conf->ssid;
        while (ssid) {
                if (!ssid->disabled)
                        return 1;
                ssid = ssid->next;
        }
        return 0;
}


static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
{
        struct wpa_supplicant *wpa_s = eloop_ctx;
        struct wpa_ssid *ssid;
        int scan_req = 0, ret;
        struct wpabuf *wps_ie = NULL;
        const u8 *extra_ie = NULL;
        size_t extra_ie_len = 0;
        int wps = 0;
#ifdef CONFIG_WPS
        enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
#endif /* CONFIG_WPS */

        if (wpa_s->disconnected && !wpa_s->scan_req) {
                wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
                return;
        }

        if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
            !wpa_s->scan_req) {
                wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
                wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
                return;
        }
        scan_req = wpa_s->scan_req;
        wpa_s->scan_req = 0;

        if (wpa_s->conf->ap_scan != 0 &&
            wpa_s->driver && IS_WIRED(wpa_s->driver)) {
                wpa_printf(MSG_DEBUG, "Using wired authentication - "
                           "overriding ap_scan configuration");
                wpa_s->conf->ap_scan = 0;
        }

        if (wpa_s->conf->ap_scan == 0) {
                wpa_supplicant_gen_assoc_event(wpa_s);
                return;
        }

        if (wpa_s->wpa_state == WPA_DISCONNECTED ||
            wpa_s->wpa_state == WPA_INACTIVE)
                wpa_supplicant_set_state(wpa_s, WPA_SCANNING);

        ssid = wpa_s->conf->ssid;
        if (wpa_s->prev_scan_ssid != BROADCAST_SSID_SCAN) {
                while (ssid) {
                        if (ssid == wpa_s->prev_scan_ssid) {
                                ssid = ssid->next;
                                break;
                        }
                        ssid = ssid->next;
                }
        }
        while (ssid) {
                if (!ssid->disabled &&
                    (ssid->scan_ssid || wpa_s->conf->ap_scan == 2))
                        break;
                ssid = ssid->next;
        }

        if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
                /*
                 * ap_scan=2 mode - try to associate with each SSID instead of
                 * scanning for each scan_ssid=1 network.
                 */
                if (ssid == NULL) {
                        wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
                                   "end of scan list - go back to beginning");
                        wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
                        wpa_supplicant_req_scan(wpa_s, 0, 0);
                        return;
                }
                if (ssid->next) {
                        /* Continue from the next SSID on the next attempt. */
                        wpa_s->prev_scan_ssid = ssid;
                } else {
                        /* Start from the beginning of the SSID list. */
                        wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
                }
                wpa_supplicant_associate(wpa_s, NULL, ssid);
                return;
        }

        wpa_printf(MSG_DEBUG, "Starting AP scan (%s SSID)",
                   ssid ? "specific": "broadcast");
        if (ssid) {
                wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
                                  ssid->ssid, ssid->ssid_len);
                wpa_s->prev_scan_ssid = ssid;
        } else
                wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;

#ifdef CONFIG_WPS
        wps = wpas_wps_in_use(wpa_s->conf, &req_type);
#endif /* CONFIG_WPS */

        if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
            !wpa_s->use_client_mlme && wps != 2) {
                wpa_s->scan_res_tried++;
                wpa_s->scan_req = scan_req;
                wpa_printf(MSG_DEBUG, "Trying to get current scan results "
                           "first without requesting a new scan to speed up "
                           "initial association");
                wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
                return;
        }

#ifdef CONFIG_WPS
        if (wps) {
                wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
                                                wpa_s->wps->uuid, req_type);
                if (wps_ie) {
                        extra_ie = wpabuf_head(wps_ie);
                        extra_ie_len = wpabuf_len(wps_ie);
                }
        }
#endif /* CONFIG_WPS */

        wpa_supplicant_notify_scanning(wpa_s, 1);

        if (wpa_s->use_client_mlme) {
                ieee80211_sta_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
                ret = ieee80211_sta_req_scan(wpa_s, ssid ? ssid->ssid : NULL,
                                             ssid ? ssid->ssid_len : 0);
        } else {
                wpa_drv_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
                ret = wpa_drv_scan(wpa_s, ssid ? ssid->ssid : NULL,
                                   ssid ? ssid->ssid_len : 0);
        }

        wpabuf_free(wps_ie);

        if (ret) {
                wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
                wpa_supplicant_notify_scanning(wpa_s, 0);
                wpa_supplicant_req_scan(wpa_s, 10, 0);
        } else
                wpa_s->scan_runs++;
}


/**
 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 * @wpa_s: Pointer to wpa_supplicant data
 * @sec: Number of seconds after which to scan
 * @usec: Number of microseconds after which to scan
 *
 * This function is used to schedule a scan for neighboring access points after
 * the specified time.
 */
void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
{
        /* If there's at least one network that should be specifically scanned
         * then don't cancel the scan and reschedule.  Some drivers do
         * background scanning which generates frequent scan results, and that
         * causes the specific SSID scan to get continually pushed back and
         * never happen, which causes hidden APs to never get probe-scanned.
         */
        if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
            wpa_s->conf->ap_scan == 1) {
                struct wpa_ssid *ssid = wpa_s->conf->ssid;

                while (ssid) {
                        if (!ssid->disabled && ssid->scan_ssid)
                                break;
                        ssid = ssid->next;
                }
                if (ssid) {
                        wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
                                "ensure that specific SSID scans occur");
                        return;
                }
        }

        wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
                sec, usec);
        eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
        eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
}


/**
 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 * @wpa_s: Pointer to wpa_supplicant data
 *
 * This function is used to cancel a scan request scheduled with
 * wpa_supplicant_req_scan().
 */
void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
{
        wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
        eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
}


void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
                                    int scanning)
{
        if (wpa_s->scanning != scanning) {
                wpa_s->scanning = scanning;
                wpa_supplicant_dbus_notify_scanning(wpa_s);
        }
}

